The present invention relates to multi-deck cage constructions for poultry and the like, and in particular to a manure shield therefor.
Multi-tier cage constructions, such as that disclosed in U.S. Pat. No. 3,768,442 to Van Huis have become the predominant system in the United States for raising poultry, and other similar livestock. In such systems, the confinement cages are arranged in at least two tiers or levels of longitudinally extending rows. The cages in each row are positioned side-by-side, and the rows are typically arranged in pairs, with a manure collection pit disposed therebetween, extending along the backs of the cages. In order to reduce the building space required to house or shelter such cage units, the rows of cages are arranged in a partially offset, pyramidal configuration. In this cage arrangement, the interior sides of the lower cage rows are disposed directly below a portion of the upper cage rows, such that the birds in the lower cages are exposed to manure droppings from the birds in the upper cage tiers.
Heretofore, various shield arrangements have been proposed to prevent manure droppings from entering the lower cages of multi-tier systems. Such shields include rigid collection plates disposed between the cage tiers, with a mechanical scraper assembly, which periodically removes the manure from the plates, and deposits it in a collection pit. Such an arrangement is disclosed in the aforementioned Van Huis patent. However, these mechanical scraper systems are relatively complex, expensive, and require periodic maintenance, which is often quite inconvenient and time consuming.
Another shield arrangment for multi-tier cage constructions is presently manufactured by Diamond, and comprises a sheet of rigid plastic which is hung from the bottom of the upper cage tiers, and covers the exposed areas of the lower tier of cages. The rigid plastic panel is relatively smooth, and disposed at a sufficient angle that it is designed to direct impinging manure droppings into the collection pit without the assistance of a mechanical scraper mechanism. However, under most circumstances, the poultry manure tends to stick to the shield, and forms a thick cake or layer which must be manually removed.
Yet another shield arrangement for multi-tier cage systems is presently manufactured by Northco, and comprises draping a lightweight sheet of fabric from the upper tier of cages, over the exposed area of the lower cage tiers, at a relatively steep angle. In this shield arrangement, the poultry droppings stick to the fabric, and because it is not supported from the back, cause the fabric panel to sag, or even rip, so that the manure is not deflected into the collection pit. Like the rigid plastic shields described above, the fabric shields become caked, and must be manually scraped or replaced.
In addition to the above described shield systems, another arrangement for handling manure droppings in multitier cage systems is disclosed in the Big Dutchman brochure entitled "PROFIT-TIER REVERSE CAGE SYSTEM," as noted in the attached Disclosure Statement. In this system, the depth of the cages (approximately 14 inches) is substantially smaller than prior cages (approximately 20 inches), and the cages are arranged in four closely spaced vertical tiers. The cage rows are tilted upwardly, such that the only exposed area of the lower tier cages is the steeply inclined rear wall, which is covered with a sheet of polyethylene, whereby manure droppings are shaken loose from the sheet by movement of the cage to which it is attached. Although this type of four-tier cage construction does alleviate the manure handling problems experienced by prior art systems, the modified cage shape, size and inclined orientation of the cages has proven to be less efficient than the standard, three-tier horizontal cage arrangement, thereby increasing the overall cost per bird of the cage construction.